Brother PT-E300 Replacement Battery BA-E001 7.4V 2600mAh

Brother PT-E300 Series — 7.4V Li-ion Replacement Battery (BA-E001)

This is a 7.4V, 2600mAh Li-ion battery replacing the Brother BA-E001 in the PT-E300 portable label printer. It also fits the PT-E500, PT-E550W, and PT-H300, along with four additional Brother label printer models sharing the same battery bay and connector. Same voltage, same form factor, direct swap.

• PT-E300 / PT-E500 / PT-H300 platform fit: These models share a 7.4V lithium cell architecture with an identical connector and BMS handshake protocol. The printer's firmware reads cell state from the battery management circuit — this replacement carries a compatible BMS that passes that check without triggering a fault state.
• Bench tested on actual hardware: We ran this cell through charge cycles on a PT-E300 unit and confirmed the BMS communicates correctly with the printer's power management board. Thermal head draw and paper feed motor start-up current both registered within normal operating range.
• PT-E300 first-install sequence: After fitting this battery, charge to full before first use, then print five test labels. The paper feed motor and thermal head calibrate their current draw profile against a fully charged cell — skipping this step can produce inconsistent print density on early jobs.

Why the PT-E550W drops its Bluetooth connection mid-label job

The PT-E550W runs both a Bluetooth radio and a thermal print head off the same battery rail. When cell voltage sags under combined load — typically below 6.8V — the printer's power management chip sheds the radio first to protect the print head. You lose the app connection, but the printer may still appear to be on. A degraded or partially discharged battery that holds 7.4V at rest can still sag hard enough under load to trigger this. Keep the cell above 50% charge during wireless print jobs to stay above that sag threshold.

Faded or uneven print on the first few labels after a battery swap

The PT-E300's thermal head uses a resistance-based heating element that requires stable voltage to reach consistent printing temperature across the full label width. A new cell that hasn't run a calibration cycle can cause the BMS to deliver slightly inconsistent current during the first few discharge events. This shows up as lighter print on one side of the label or variable line density. Run five full-width test labels at maximum contrast setting — by label five, the BMS current profile stabilises and print consistency normalises.